I'm not an expert but had a secondary minor in French so will attempt an answer. Maybe Blue or someone else from France will answer.
The last letter in a French word is often silent. If you mean the city of Nantes, it is pronounced as one syllable with a somewhat nasal sound--close to nont. Anjou according to a gazetteer is ah-zhoo with a nasal "A" sound. It didn't give Saumur but I think it would be close to so-mur. Touraine is close to too-ren.